Router attachment



Dec. 22, 1964 B. D. LACEY 3,162,221

ROUTER ATTACHMENT Filed July 25, 1962 INVENTOR BURL D. LACEY E w. W

ATTORNEY -United States Patent Ofllice 3,162,221 Patented Dec. 22, 1964 3,162,221 ROUTER ATTACHMENT Burl D. Lacey, 7486 Potter Road, Davison Township, Genesee (Iounty, Mich. Filed July 25, 1962, Scr. No. 212,274 3 Claims. (U. 144-134) The present invention relates to portable routers and more particularly to router means adapted for attachment to a portable electric drill.

An object of the invention is to provide improved routing means adapted for attachment to a portable electric drill.

Another object of the invention is to provide improved means for releasably attaching routing means to a portable electric drill.

Still a further object of the invention is to provide, in a router attachment for a portable electric drill, having a stepped housing, improved means for positively limiting the depth to which said stepped housing is received by said router attachment.

These, and other objects of the invention which will become apparent from a consideration of the following description and the appended claims, are attained by the present invention, a preferred embodiment of which has con illustrated, by way of example only, in the accompanying drawing, forming a part of this specification, in which like characters are employed to designate like parts throughout the same, and wherein:

FIGURE 1 is a side elevational view showing a router attachment operatively connected to a portable electric drill.

FIGURE 2 is a sectional view taken along line 22 of FIGURE 1.

FIGURE 3 is a sectional view taken along line 3-3 of FIGURE 2.

Referring now more particularly to the drawing, a conventional portable electric drill is generally indicated at and includes a housing 12. Housing 12 is reduced in diameter near the forward end thereof first to a cylindrical neck 14 and, in turn, by an abrupt shoulder 16 to a cylindrical throat 18. A conventional rotatable chuck 20 extends outwardly from housing 12 through throat 18 and is adapted to releasably secure the shank 22 of a router bit 24 in the conventional manner.

Drill bears a conventional trigger 28, releasable switch lock 29, and electrical switch (not shown) for controlling the flow of electrical current transmitted to an electrical motor (not shown) within housing 16 by an electrical cord 3d, to cause rotation of chuck 2i) and router bit 24 in the conventional manner.

A cylindrical bushing 31 is provided having an axially aligned bore 32 and counterbore 34, the diameters of said bore and counterbore, respectively, being carefully selected so as to snugly receive throat 18 and neck 14 of the particular make and model of drill 10 with which the router attachment is adapted for use. A shoulder 36, formed by the juncture of counterbore 34 and bore 32, is disposed to engage shoulder 16 by abutment therewith when throat 13 and neck 14 are received within bore 32 and counterbore 34, for a specific and unique purpose more particularly hereinafter described.

The upper portion of bushing 31 is bifurcated diametrically into two opposing semicircular segments 33 and 40. As best-shown in FIGURE 2, one end of segment 38 proximate to an end of segment 40 disposed in opposition thereto is provided with a tangential bore and counterbore generally indicated at 42, to receive a machine screw 44; segment 40 is drilled and tapped coaxially with said bore and counterbore to threadably receive the threaded end of the screw as shown at 46. Segment 4%) is similarly provided, at the other end of the bifurcation, with a bore and counterbore generally indicated at 48 to receive a similar machine screw 50, and segment 38 is similarly drilled and tapped at 52 to similarly threadably receive screw 50. When the stepped portion of housing 12 is received within bushing 31, in such manner that neck 14 is disposed within counterbore 34 and between segments 38 and 40, throat 18 is disposed within bore 32, and shoulder 16 is in abutment with shoulder 36, segments 38 and 40 may be drawn toward each other and tightly clamped against neck 14 by tightening screws 44 and 50. Bushing 31 will thus be securely but releasably attached to housing 12.

A plurality of external threads 54 is provided surrounding the cylindrical exterior of bushing 31 and adapted to be threadably engaged by internal threads 56 of a lock nut 57.

A sleeve 58, preferably cylindrical in cross section, is provided and bears an integral, inwardly-directed, annular top flange 6% having internal threads 61 arranged to threadably receive bushing 31 by engagement with threads 54. An external circular flange 62 is. provided surrounding the end of sleeve 58 opposite flange 60 and is preferably cast or turned integral with the sleeve. A pair of handles 64, formed of any suitable material such as plastic, hard rubber, metal, or the like, is secured by any conventional means, such as an adhesive (not shown) to a pair of metal stems 66, 66, respectively, the other ends of the stems being secured by brazing (not shown) or other convenient means within a pair of bores 68, 68 drilled diagonally into flange 62 and cylinder 58. A pair of substantial viewing apertures 79, '72 is provided in the sidewall of cylinder 58 to afford the operator observation of the progress of the routing operation.

To assemble the device, bushing 31 is first secured to housing 12 in the manner hereinabove described and lock nut 57 isthreaded upon the bushing. Sleeve 53 is then threaded upon bushing 31 until router bit 24 extends below the lower surface of flange 62 the precise distance required to eifect a router cut of the desired depth below said lower surface of said flange. The distance which router bit 24 extends beyond flange 68, and hence the .depth of the routing cut to be made thereby, may be delicately and accurately adjusted by rotating sleeve 58 with respect to bushing 31, whereby threads 54 and 61 will cause the sleeve to move axially with respect to the bushing. The pitch of threads 54 and 61 may be selected to provide any desired degree of accuracy. When sleeve 58 has been thus positioned upon bushing 31 to provide the desired extension of router bit 24 below flange 62 and the corresponding depth of the routing cut to be effected thereby, lock nut 57, borne by bushing 31, is tightened against the upper surface of flange 60, thereby preventing further rotation of sleeve 58 with respect to the bushing. Accidental variation from adjustment to the selected depth of routing cut is thus eliminated.

In operation, with the router attachment thus assembled and attached to drill 10, the router bit 24 is placed operatively against a workpiece (not shown) with the axis of shank 22 normal to the surface of the workpiece, and drill 10 is switched on in the conventional manner, whereby the router bit is caused to rotate and to rout out the portion of the workpiece contacted by the router bit. When the desired depth of routing cut has been effected in the workpiece, the lower surface of flange 62 will be disposed flush against the upper surface of the workpiece, thereby preventing router bit 24 from removing material from the workpiece to any greater than the preselected depth. Handles 64, 64 are manually gripped by the operator and sleeve 58, with drill 10 supported thereon, may be moved parallel to the surface of the workpiece and with flange 68 resting upon the surface thereof, whereby the operator may effect routing out of the debushing 31, beingabutted by shoulder 16 of housing 12,

positively limits the depth to which the housing is received within bushing 31. Absolute, protection is thereby afforded against accidental downward slippage of the housing within bushing 31 and consequent routing out the workpiece to a depth greater than that desired, which might otherwise occur should the weight of drill 10, or

the operator by bearingdownward upon the drill, overcome the frictional restraint to such movement provided by the clamping-action of segments 38 and 40 against neckv 14.

by adjusting said sleeve along said bushing the amount which the router bit projects beyond said work engaging portions'can be adjusted to control the depth of cut of the work by the router bit.

2. A router attachment for a conventional electric hand drill having a cylindrical neck and a cylindrical throat connected by a shoulder, and also having a rotatable chuck adapted to releasably engagethe shank of I a router bit, the combination comprising:

' 'Sleeve 58 may be used with any make or model of drill 10 having a stepped housing similar to that provided by neck 14 and throat 18, regardless of the particular diameters of such neck and throat of the particular make and model, by utilizing in conjunction therewith a selected bushing 31 having bore 32 and counterbore 34 of such diameters as to snugly receive the throat 18 and the neck 14 and to provide abutment of shoulder 36 with the shoulder 16 of such particular make and model of drill. A plurality of bushings 31 may thus be provided, each adapted for use with a particular conventional make or model of drill and all adapted for engagement with a single sleeve 58.

It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred embodiment of the same and that resort may be had to various changes inconstruction Without departing from the scope of the invention or the subjoined claims;

What is claimed is: V 1., A portable router comprising:

an electric hand drill housing containing an electric motor and having near its forward end a cylindrical neck followed by a cylindrical throat of reduced diameter, there being a substantially radially extending shoulder between said throat and said neck;

a rotatable chuck extending outwardly from said housing through said throat and adapted to releasably engage the shank of a'router bit to support same for rotation but to hold same against axial movement with respect to said housing;

a cylindrical bushing having a throughbore and a 'counterbore at one end thereof, said neck extending into said counterbore with'said shoulder abutting against the radial end wall-of said counterbore, said throat extending through said throughbore, said bushing being axially split partway along its length to divide the inner portion thereof into two opposed arcuate segments, ibolt means extending between said segments for drawing said segments toward each other into clamping engagement with said neck whereby said onto the external threads on said i I lockable in fixed position on said bushing by thread ing said lock nut into engagement with said end wall,

said sleeve having a substantially cylindrical side wall integral with said end wall and extending away from the bushing, said sleeve surrounding and being spaced from the router bit, 'said side wall having viewing apertures therethrough so that the operator can view the routing operation, said side wall also having work engaging portions at the other end thereof, whereby a cylindrical bushing having a through-bore and a counterbore at one end thereof, ,said neck being extendable into said counterbore with said shoulder abutting against the radial end Wall of said counterbore and said throat extending through said through bore, said bushing being axially split partway along its length to divide the inner portion thereof into two arcuate segments, bolt means extending between said segments for drawing said segments toward each other into clamping engagement'with said" neck whereby said bushing can be fixed to said housing, said bushing being externally threaded along its entire length;

a lock out threaded onto the external threads on said bushing; V i

a sleeve having at one end thereof an end wall with a threaded central opening into which the forward end of said bushing is threaded whereby said sleeve can be moved along said bushing and thereby with re- .spect to said housing by rotation of said sleeve with respect to said bushing, said sleeve being releasably lockable in fixed position on said bushing by threading said lock nut into engagement with said end wall, said sleeve having a substantially cylindrical side wall integral with said end wall and extending away from the bushing, said side wall surrounding and being spaced from the router bit, said side wall having viewing apertures therethrough so that the operator can view the routing operation, said side wall also having work engaging portions at the other end thereof, whereby by adjusting said sleeve along said bushing the amount which the router bit projects beyond said work engaging portions can be adjusted to control the depth of cut of the work by the-router 3. A portable router, comprising:

an electric hand drill housing containing an electric motor and having near its forward end a cylindrical neck means; p

a rotatable chuck extending outwardly from said housing through said neck means and adapted to releasably engage the shank of a router bit to support same for rotation but to hold same against axial movement with respect to said housing;

a cylindrical bushing having a throughbore, said neck means extending into said throughbore, said bushing being axially split at least partway alongits length to divide the inner end portion thereof into a plurality of arcuate segments, fastening'means extending between said segments for drawing said segments toward each other into clamping engagement with said neck means whereby said-bushing-is fixed to said housing,-said bushing being externally threaded along at least a substantial portion of its length;

a lock nut threaded onto the external threads on said bushing;

a sleeve havingat one end thereof an end Wall with a threaded-central opening into which the forward end of said bushing is, threaded whereby said sleeve can be moved along said bushing and thereby with respect to saidhousing by rotation of said sleeve with respect to saidv bushing, said sleeve being releasably ,lockable in fixed positionon said bushing by threading said lock nut into engagement with'said end wall,

, said sleeve having a substantially cylindrical side wall integral with said end wall and extending away from the bushing, said sleeve surrounding and being spaced from the router bit, said side wall having viewing apertures therethrough so that the operator can view the routing operation, said side wall also having work engaging portions at the other end thereof, whereby by adjusting said sleeve along said bushing the amount which the router bit projects beyond said work engaging portions can be adjusted to control the depth of cut of the work by the router bit.

References Cited in the file of this patent UNITED STATES PATENTS Beutner May 26, 1931 Turnbull Mar. 3, 1953 Hollien et a1. Oct. 1, 1957 Dernarkis Aug. 11, 1959 Dodegge Nov. 21, 1961 Quackenbush May 15, 1962 FOREIGN PATENTS France Mar. 31, 1954 

1. A PORTABLE ROUTER COMPRISING: AN ELECTRIC HAND DRILL HOUSING CONTAINING AN ELECTRIC MOTOR AND HAVING NEAR ITS FORWARD END A CYLINDRICAL NECK FOLLOWED BY A CYLINDRICAL THROAT OF REDUCED DIAMETER, THERE BEING A SUBSTANTIALLY RADIALLY EXTENDING SHOULDER BETWEEN SAID THROAT AND SAID NECK; A ROTATABLE CHUCK EXTENDING OUTWARDLY FROM SAID HOUSING THROUGH SAID THROAT AND ADAPTED TO RELEASABLY ENGAGE THE SHANK OF A ROUTER BIT TO SUPPORT SAME FOR ROTATION BUT TO HOLD SAME AGAINST AXIAL MOVEMENT WITH RESPECT TO SAID HOUSING; A CYLINDRICAL BUSHING HAVING A THROUGHBORE AND A COUNTERBORE AT ONE END THEREOF, SAID NECK EXTENDING INTO SAID COUNTERBORE WITH SAID SHOULDER ABUTTING AGAINST THE RADIAL END WALL OF SAID COUNTERBORE, SAID THROAT EXTENDING THROUGH SAID THROUGHBORE, SAID BUSHING BEING AXIALLY SPLIT PARTWAY ALONG ITS LENGTH TO DIVIDE THE INNER PORTION THEREOF INTO TWO OPPOSED ARCUATE SEGMENTS, BOLT MEANS EXTENDING BETWEEN SAID SEGMENTS FOR DRAWING SAID SEGMENTS TOWARD EACH OTHER INTO CLAMPING ENGAGEMENT WITH SAID NECK WHEREBY SAID BUSHING IS FIXED TO SAID HOUSING, SAID BUSHING BEING EXTERNALLY THREADED ALONG AT LEAST A SUBSTANTIAL PORTION OF ITS LENGTH; A LOCK NUT THREADED ONTO THE EXTERNAL THREADS ON SAID BUSHING; A SLEEVE HAVING AT ONE END THEREOF AN END WALL WITH A THREADED CENTRAL OPENING INTO WHICH THE FORWARD END OF SAID BUSHING IS THREADED WHEREBY SAID SLEEVE CAN BE MOVED ALONG SAID BUSHING AND THEREBY WITH RESPECT TO SAID HOUSING BY ROTATION OF SAID SLEEVE WITH RESPECT TO SAID BUSHING, SAID SLEEVE BEING RELEASABLY LOCKABLE IN FIXED POSITION ON SAID BUSHING BY THREADING SAID LOCK NUT INTO ENGAGEMENT WITH SAID END WALL, SAID SLEEVE HAVING A SUBSTANTIALLY CYLINDRICAL SIDE WALL INTEGRAL WITH SAID END WALL AND EXTENDING AWAY FROM THE BUSHING, SAID SLEEVE SURROUNDING AND BEING SPACED FROM THE ROUTER BIT, SAID SIDE WALL HAVING VIEWING APERTURES THERETHROUGH SO THAT THE OPERATOR CAN VIEW THE ROUTING OPERATION, SAID SIDE WALL ALSO HAVING WORK ENGAGING PORTIONS AT THE OTHER END THEREOF, WHEREBY BY ADJUSTING SAID SLEEVE ALONG SAID BUSHING THE AMOUNT WHICH THE ROUTER BIT PROJECTS BEYOND SAID WORK ENGAGING PORTIONS CAN BE ADJUSTED TO CONTROL THE DEPTH OF CUT OF THE WORK BY THE ROUTER BIT. 